1. Field of Invention
This invention relates to iterative decoding of input sequences.
2. Description of Related Art
Maximum a posteriori (MAP) sequence decoding selects a most probable information sequence X1T=(X1,X2, . . . , XT) that produced the received sequence Y1T=(Y1,Y2, . . . , YT). For transmitters and/or channels that are modeled using Hidden Markov Models (HMM), the process for obtaining the information sequence X1T that corresponds to a maximum probability is difficult due to a large number of possible hidden states as well as a large number of possible information sequences X1T. Thus, new technology is needed to improve MAP decoding for HMMs.